In every incarnation of Batman I've ever seen, whenever he uses his grappling hook, it always hits the target and does whatever he needs it to do, such as saving himself and the person he dove over the cliff to save, or to catch the bad guy he knocked off the cliff but now wants to save. It doesn't seem to matter if it's the grapple gun, or the simple one he has to spin and throw himself.
Why is this?
The Wikipedia entry has this to say about it:
A handheld grappling hook that shoots out a claw-shaped projectile on a retractable high-tensile cord, which grabs onto a surface.
The hook is secured to the belt magnetically rather than being contained in the belt. It has been portrayed as a portable grappling hook line to be manually thrown onto a higher surface or vantage point for him to climb it to the targeted area. However, in more recent incarnations, his overall grappling gear is composed of a line-launching, gun-like device that shoots the line to pull Batman towards his targeted area or to pull a target towards Batman.
None of this describes how it always grabs onto a surface. I'm aware each continuity's grappling tech might not be exactly the same, but I'm wondering if there's any common denominator that they might share that could explain this phenomenon.